Compound bend in frame rails

[GMracer]

On my project the front rails sweep up and bend inwards and I have talked to both AutoWeld and Art Morrison and both have told me it's impossible to replicate that kind of bend, so I was going to fabricate the bend with some 90*s but AutoWeld told me what they do is bend it straight (the easy way) then pie cut three sides and bend it inwards and lay a nice penetrating weld down the seam and clean it up. Does that sounds like a good idea? I figure I may even plate that joint after for added strength but I wanted to see if anyone here was against it, and if so why?

[68protouring454]

i would just miter cut it or modify chassis and run front rails at same width from under the car, i ran into this problem also most of the mandrel guys need 6 inches inbetween bends, thus creating the issue with the rise part of the chassis as most of the time its less then 12 inches you need both bends.
i would miter cut the pieces then weld grind smooth and fish plate on the inside.

p.s by miter cutting it you can jig your upper rail in place, cut corresponding angle on upper rail, then notch tube to rest on lower rail and compound miter cut the upper cut so it lays inward and mate to the upper rail nicely.

[68protouring454]

i would just miter cut it or modify chassis and run front rails at same width from under the car, i ran into this problem also most of the mandrel guys need 6 inches inbetween bends, thus creating the issue with the rise part of the chassis as most of the time its less then 12 inches you need both bends.
i would miter cut the pieces then weld grind smooth and fish plate on the inside.

[GMracer]

I thought about that too, but I'm wondering if what I stated above would be structural sound, I've seen it done and still has a nice mandrel look to it, too a point of course

[deuce_454]

check out rad rides by troys HP, he has a few frames built from 4 flat sides with the edges massaged and welded together to give a totally OEM look...

[deuce_454]

this could be done by setting the pieces of frame opposite eachother in a jig-- bridge the gap with 4 bent tubes in the corners of the rectangular frame... and "boxing" the structure bu adding the sides in flat stock.. that way when you grind the welds you will end up with a compound bent square tube with rounded corners and edges parallel to the OEM frame

[Silver69Camaro]

GM Racer, shoot me an email with a drawing (including dimensions) and I'll see if I can help you out.

[GMracer]

thanks Matt I actually sent some to Kevin and he brought them over to the engineering dept. there and you guys drew stuff up for me, you couldn't to such a drastic drop and sweep. But you showed my when you could do, but it just wouldn't work.

[GMracer]

Originally Posted by deuce_454

this could be done by setting the pieces of frame opposite eachother in a jig-- bridge the gap with 4 bent tubes in the corners of the rectangular frame... and "boxing" the structure bu adding the sides in flat stock.. that way when you grind the welds you will end up with a compound bent square tube with rounded corners and edges parallel to the OEM frame

didn't even see your post, that is a good idea, however I don't have a tube bender. I think Im going to do the pie cut, but add an internal plate on the face of it, it'll be trick to get in there and weld once it's closed up but I'm sure I could work something out. Maybe even add an external one too. Seems like the easiest way to go about this situation with the tools and experience I have.

[Vince@Meanstreets]

Originally Posted by deuce_454

check out rad rides by troys HP, he has a few frames built from 4 flat sides with the edges massaged and welded together to give a totally OEM look...

Be the only way in this instance. That would be alot of miter work other wise.